Why are the people who always say they need to go on a Diet the kind of people that dont need to go on a Diet, and the people that do need to, think they don't. Word of advice, if you can't fit through a doorway sideways, you need to go on a diet.
People who you say don't need to are doing it because they want to keep their form and there is nothing wrong with that. I love food, so I'll go for smaller portion sizes and eat proper portion sizes throughout the day so I don't feel hungry, but more importantly I keep to my exercise routine.
Most people that I find who do need to are eating huge portion sizes. There is nothing wrong with loving a certain food, as long as you can control yourself. You don't have to eat that tasty cheese burger 5 times a week. You don't need to get a double, or a triple, you don't need to increase to a large fry and a large drink. Stop drinking unhealthy drinks and find something that is cheap and you enjoy, then you can make a huge batch of it and store it in the fridge so you can just get a cup and fill your glass up.
You can make good food at home at a fraction of the cost it takes to go out, you'll get more food out of it and it will end up tasting better as long as you practice doing it.
I learned how to cook very young so I had my whole childhood to learn how to cook and make good food. People who didn't are now under the restraints of their daily life and they feel that they don't have enough time to cook in the day which is probably true depending on what you do. I'd recommend to those people to practice on your days off, but more importantly freeze slow cooker meals so you can take it out and put it in the slow cooker before you go to work or school, then when you come home you have a nice warm
good meal that tastes like you spent hours making it.
Most people won't go on a diet because they love to eat and they don't want to give it up, but they also are eating too much and not taking care of themselves enough to eat the way they are currently.